Drill rigs have utilized several methods for transferring tubular members from a pipe rack adjacent to the drill floor to a mousehole in the drill floor or the well bore for connection to a previously transferred tubular or tubular string. The term “tubular” as used herein includes all forms of pipe, drill pipe, drill collars, casing, liner, bottom hole assemblies (BHA), and other types of tubulars known in the art.
Conventionally, drill rigs have utilized a combination of the rig cranes and the traveling system for transferring a tubular from the pipe rack to a vertical position above the center of the well. The obvious disadvantage with the prior art systems is that there is a significant manual involvement in attaching the pipe elevators to the tubular and moving the pipe from the drill rack to the rotary table at the wellhead. This manual transfer operation in the vicinity of workers is potentially dangerous and has caused numerous injuries in drilling operations. Further, the hoisting system may allow the tubular to come into contact with the catwalk or other portions of the rig as the tubular is transferred from the pipe rack to the drill floor. This can damage the tubular and may affect the integrity of the connections between successive tubulars in the well.
In the past, various devices have been created which mechanically move a pipe from a horizontal orientation to a vertical orientation such that the vertically-oriented pipe can be installed into the well bore. Typically, these devices have utilized several interconnected arms that are associated with a boom. In order to move the pipe, a succession of individual movements of the levers, arms, and other components of the boom must be performed in a coordinated manner in order to achieve the desired result. Typically, a wide variety of hydraulic actuators are connected to each of the components so as to carry out the prescribed movement. A complex control mechanism is connected to each of these actuators so as to achieve the desired movement. Advanced programming is required of the controller in order to properly coordinate the movements in order to achieve this desired result.
Unfortunately, with such systems, the hydraulic actuators, along with other components, can become worn with time. Furthermore, the hydraulic integrity of each of the actuators can become compromised over time. As such, small variations in each of the actuators can occur. These variations, as they occur, can make the complex mechanism rather inaccurate. The failure of one hydraulic component can exacerbate the problems associated with the alignment of the pipe in a vertical orientation. Adjustments of the programming are often necessary so as to continue to achieve the desired results. Fundamentally, the more hydraulic actuators that are incorporated into such a system, the more likely it is to have errors, inaccuracies and deviations in the desired delivery profile of the tubular. Typically, very experienced and knowledgeable operators are required to carry out this pipe movement operation. This adds significantly to the cost associated with pipe delivery.
To address these problems and needs, U.S. application Ser. No. 11/923,451, filed on Oct. 24, 2007 by the present applicant, discloses a pipe handling apparatus that has a boom pivotally movable between a first position and a second position, a lever assembly pivotally connected to the boom, an arm pivotally connected at one end to the first portion of the lever assembly and extending outwardly therefrom, a gripper affixed to an opposite end of the arm suitable for gripping a diameter of the pipe, a link pivotally connected to the lever assembly and pivotable so as to move relative to the movement of the boom between the first and second positions, and a brace having one end pivotally connected to the boom and an opposite end pivotally connected to the arm between the ends of the arm. The lever assembly has a first portion extending outwardly at an obtuse angle with respect to the second portion.
The pipe handling apparatus delivers a pipe to a wellhead when in the second position. The boom of the above pipe handling apparatus is pivotally connected to a skid so as to pivot between the first and second positions. Pipes can be of extraordinary lengths and weights; therefore, the pivotal connection between the boom and skid must be strong so as to withstand the forces created by the movement of the boom between the first and second positions. Typically, hydraulic cylinders are placed between the boom and skid so as to raise and lower the boom between the first and second positions. The hydraulic cylinders are connected to a hydraulic power system so as to raise and lower the boom between the first and second positions. Through use of the above-discussed pipe handling apparatus, it was found that large amounts of power are needed for certain portions of the power band of the stroke of the hydraulic cylinders. That is, the power requirements for extending the hydraulic cylinders so as to move the boom between the first and second positions is not uniform for the entire movement of the hydraulic cylinders. Thus, there is a need to make the power band of the hydraulic cylinders more uniform across the entire length of travel of the hydraulic cylinders. Moreover, there is a need to reduce the total energy required to move the boom between the first and second positions.
Various patents have issued relating to the movement of a boom of a pipe handling apparatus with hydraulic cylinders or other similar means. For example, U.S. Pat. No. 7,077,209, issued on Jul. 18, 2006 to McCulloch et al., discloses a mast for lifting and suspending a coiled tubing injector and blowout preventer over a wellhead that is pivotally mounted on a rear portion of a truck. The mast has two side-by-side telescoping legs that extend and retract synchronously. Hydraulic cylinders pivotally move the mast between a lower position and an upper position.
U.S. Pat. No. 4,336,840, issued on Jun. 29, 1982 to Bailey, discloses a suspension system for use with a mast. The system has two or more fluid pressure piston-and-cylinder assemblies. The cylinders are linked in pairs so that retraction of both piston rods reduces the length of the pair of assemblies to the length of a single assembly. Operation of both pistons in a pair provides an effective stroke twice the length of a single assembly stroke. In a particular embodiment, a double cylinder system is used as a pickup system for elevating equipment along a mast in a well work over rig.
U.S. Pat. No. 7,289,871, issued on Oct. 30, 2007 to Williams, discloses a drilling apparatus that has a base from which a drilling arm is pivotally mounted. The drilling arm has an inner arm and an outer arm. The inner arm has a first end and a second end. The first end is pivotally connected by a first pivot joint to the base. The outer arm has a first end and a second end. The second end of the inner arm is pivotally connected via a second pivot joint to the first end of the outer arm. A drill-mounting assembly is positioned at the second end of the outer arm. Actuation of the inner and outer arms is achieved by hydraulic cylinders. Proper operation of the cylinders causes the second end of the outer arm to follow a substantially linear path.
U.S. Pat. No. 6,003,598, issued on Dec. 21, 1999 to Andreychuk, discloses a mobile hybrid rig adapted to run coiled tubing and wireline equipment for oil and gas wells. The rig has a chassis and power unit for transporting the rig. An adjustable platform with a number of hydraulically-operated stabilizers aligns the tubing at the wellhead. A mast is pivotable into slanted or vertical positions for coil tubing operation with a blowout preventer and an injector. A cradle supports and aligns an injector to the wellhead. A coil-tubing reel cartridge assembly is adapted to run coil-tubing reels. A winching facility is used to manipulate wireline equipment. A control cabin is used to manage rig activities.
U.S. Pat. No. 6,234,253, issued on May 22, 2001 to Dallas, discloses a method and apparatus for servicing a well. The apparatus has a pair of hydraulic cylinders pivotally mounted to a pair of base beams. The cylinders are movable from a horizontal position for transportation to a vertical position for operation. In the vertical position, the cylinders flank a wellhead and are adapted to lift the wellhead and attached production tubing using a workover beam and a lifting sub. The wellhead and production tubing can be rotated during or after elevation. A motor can be mounted to the workover beam to rotate the wellhead and the tubing. A calibrated pressure gauge can be used to indicate the weight being lifted. The apparatus can be connected to a crane truck.
U.S. Pat. No. 6,264,128, issued on Jul. 24, 2001 to Shampine et al., discloses a levelwind system for a coiled-tubing reel that has an arcuate guide arm extending over the upper surface of the reel, a universal joint mounted to the lower end of the arm, a guide member supported on the free end of the guide arm, a lift cylinder for raising and lowering the guide arm, a balancing cylinder for moving the guide arm laterally, and a hydraulic fluid circuit that is responsive to a position sensor and a microprocessor.
U.S. Pat. No. 6,431,286, issued on Aug. 13, 2002 to Andreychuk, discloses an injector arrangement for use in a rig that has a movable carrier, a derrick tiltably mounted to the carrier, and a trolley capable of sliding along the derrick. An injector cradle is movable along the trolley in at least a plane perpendicular to the derrick and is pivotally mountable beneath the trolley. An injector is supported at its upper end from the cradle. At least two hydraulic cylinders are supported at one end by the derrick. The cylinders are engaged at an opposed end to a lower end of the injector.
U.S. Pat. No. 6,502,641, issued on Jan. 7, 2003 to Carriere et al., discloses a hybrid apparatus for operation with both coiled tubing and sectional tubing that has a coiled-tubing rig. The rig has a frame, a mast normally aligned over a wellhead, an injector located on the mast, and a tubing straightener positioned between the injector and the wellhead. A rotary table is affixed to the wellhead for rotationally supporting tubing passing through the wellhead. A jib crane is mounted atop the mast. A mechanism pivots the mast between a first position and a second position.
It is an object of the present invention to reduce operating pressures of hydraulic cylinders connected to the boom of a pipe handling apparatus.
It is another object of the present invention to decrease the duty of hydraulic cylinders of a pipe handling apparatus.
It is another object of the present invention to reduce the peak and average horsepower requirements for pivoting a boom of a pipe handling apparatus.
It is still another object of the present invention to reduce peak cooling requirements while lowering the boom of a pipe handling apparatus.
It is another object of the present invention to reduce fuel consumption due to pivoting a boom of a pipe handling apparatus by up to seventy-five percent.
It is another object of the present invention to create negative gravity accelerations while lowering the boom of a pipe handling apparatus so as to almost “float” the boom.
It is another object of the present invention to provide extra capacity or speed in horse power of a pipe handling apparatus.
It is still another object of the present invention to increase the useful life and reliability of a pipe handling apparatus.
It is another object of the present invention to create lifting mechanisms for a boom of a pipe handling apparatus that are completely separate sub systems that have no significant impact on raising the boom or controlling the boom.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.